A detailed study has been made of the dosimetry of total skin electron irradiation. This study has quantified and improved the whole skin treatments received by patients with mycosis fungoides. The treatment technique has now been updated and implemented on the new Clinac 20 linear accelerator. A study has been started to selectively and locally modify the fluence rate to allow for the locally higher dose rates to the hands and feet, which now require cumbersome shielding over part of the treatment course.